The effect of area on pulsed breakdown in water

Experimental results are presented on the degree to which electrode surface area impacts the dielectric strength of water. A water gap of 4 mm was tested under pulsed conditions with a maximum electric field in excess of 1 MV/cm and a maximum current of more than 20 kA. Stainless steel electrodes with a Bruce profile were used to generate a uniform electric field across the water gap. The profile of the electrodes enabled effective areas ranging from 0.5 cm² to 75 cm² while minimizing the change in capacitance of the water gap. Conclusions are made as to the effect electrode surface area has on the holdoff voltage and holdoff time of water dielectric systems